Cooling module

ABSTRACT

A cooling module comprises an intercooler  100  and an integrated heat exchanger  1  including a condenser unit  200  for cooling a refrigerant circulated in a refrigeration cycle by heat exchange between the refrigerant and air and an oil cooler unit  300  for cooling an oil higher in temperature than the refrigerant by heat exchange between the oil and air. Condenser unit  200  and oil cooler unit  300  are vertically arranged in parallel to each other, and integrated heat exchanger  1  is arranged downstream of intercooler  100  in the air flow. The vertical length of integrated heat exchanger  1  is larger than the vertical length of intercooler  100 . Oil cooler unit  300  is arranged in superposition with at least a part of intercooler  100  as viewed from the direction of air flow.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a cooling module comprising a heat source unitand an integrated heat exchanger having a plurality of heat exchangeunits.

2. Description of the Related Art

Vehicles such as automobiles are equipped with many heat exchangers suchas an oil cooler for cooling oil in the torque converter of an automatictransmission and an oil cooler for cooling engine oil, as well as aradiator for cooling water circulating through an engine and a condenserfor cooling refrigerant of an air conditioning system. A hybrid vehiclealso includes a radiator for cooling electronic parts, such as aninverter for controlling the electric motor.

In recent years it has been desirable to reduce the thickness and sizeof heat exchangers in order to safely prevent damage due to vehiclecollision by reducing the installation space and assembly of heatexchangers. As a method for size reduction, an integrated heat exchangerhas been proposed in which the interior of each pair of left and rightheaders (tanks) of a heat exchanger are partitioned by a partitioningplate so that one heat exchanger core has independent dual heat exchangefunctions of the condenser unit and the oil cooler unit (see, forexample, U.S. Pat. No. 6,394,176).

SUMMARY OF THE INVENTION

In a vehicle having an intercooler (heat source unit) for coolingcombustion air (intake air) introduced into an internal combustionengine, the intercooler is often arranged under the bumper where air canbe introduced from the vehicle front. The heat exchange capacity of theintercooler changes according to the running load, and under a maximumload, air downstream of the intercooler reaches a temperature about 30°C. higher than atmospheric temperature. In the case where theatmospheric temperature is 30° C., for example, the air temperaturedownstream of the intercooler in the air flow reaches a maximum of 60°C., thereby generating conditions surpassing the condensationtemperature (about 40 to 45° C.) of the refrigerant of the condenserunit.

Under these conditions, the arrangement of the condenser unit downstreamof the intercooler in the air flow poses the problem that the heatexchange performance of the condenser unit is extremely reduced.

Especially, in the case where the condenser unit of the integrated heatexchanger includes a condensing portion for condensing a gas-phaserefrigerant by heat exchange between the gas-phase refrigerant and air,and a supercooling portion for further cooling the refrigerant by heatexchange between the condensed refrigerant and air, the arrangement ofthe supercooling portion downstream of the intercooler in the air flowcauses the refrigerant to boil in the supercooling portion. As a result,the expansion valve arranged downstream of the condenser unit in therefrigerant flow runs short of refrigerant, thereby deterioratingcooling performance. Another problem is that the gas-phase refrigerantflows into the expansion valve and noise is generated from the expansionvalve.

In view of the problems described above, the object of this invention isto provide a cooling module in which an integrated heat exchanger havinga condenser unit and another heat exchange unit arranged downstream of aheat source unit in the air flow, and in which the heat exchangeperformance of the condenser unit is secured.

In order to achieve the object described above, according to a firstaspect of the invention, there is provided a cooling module comprising aheat source unit 100 and an integrated heat exchanger 1 including acondenser unit 200 for cooling a refrigerant circulated in arefrigeration cycle by heat exchange between the refrigerant and air andanother heat exchange unit 300 for cooling another fluid by heatexchange between another fluid higher in temperature than therefrigerant and air, wherein condenser unit 200 and heat exchange unit300 are vertically juxtaposed, wherein integrated heat exchanger 1 isarranged downstream of heat source unit 100 in the air flow, wherein thevertical length of integrated heat exchanger 1 is larger than thevertical length of heat source unit 100, and wherein another heatexchange unit 300 is arranged in superposition with at least a part ofheat source unit 100 as viewed from the direction of air flow.

As described above, another heat exchange unit 300 for cooling anotherfluid higher in temperature than the refrigerant in the condenser unit200 is arranged downstream of the heat source unit 100 in the air flow,i.e. at the area high in air temperature. Therefore, the condenser unit200 can be arranged at an area comparatively low in air temperature. Asa result, heat exchange performance of the condenser unit 200 can besecured.

The condenser unit 200 of the cooling module according to the firstaspect described above may be comprised of a condensing portion 210 forcondensing the refrigerant and supercooling portion 220 in order tosupercool the refrigerant flowing in from the condensing portion 210.

According to a second aspect of the invention, there is provided acooling module comprising a heat source unit 100 and an integrated heatexchanger 1 including a condenser unit 200 for cooling a refrigerantcirculated in a refrigeration cycle by heat exchange between therefrigerant and air and another heat exchange unit 300 for coolinganother fluid by heat exchange between another fluid higher intemperature than the refrigerant and air, wherein the condenser unit 200and another heat exchange unit 300 are vertically juxtaposed, whereinthe integrated heat exchanger 1 is arranged downstream of the heatsource unit 100 in the air flow, wherein the vertical length of theintegrated heat exchanger 1 is larger than the vertical length of theheat source unit 100, wherein the condenser unit 200 includes acondensing portion 210 for condensing the refrigerant and a supercoolingportion 220 for supercooling the refrigerant flowing in from thecondensing portion 210, and wherein the supercooling portion 220 isarranged not to be superposed with the heat source unit 100 as viewedfrom the direction of the air flow.

In the condenser unit 200, the supercooling portion 220 which isrequired to be kept at a low temperature is arranged downstream of theheat source unit 100 in the air flow, i.e. at an area high in airtemperature, therefore, heat exchange performance of condenser unit 200can be secured. In the process, refrigerant which may boil at thesupercooling portion 220 can be suppressed, and therefore, insufficientrefrigerant flow rate which otherwise might occur in the expansion valvearranged downstream of the condenser unit 200 in the refrigerant flowcan be suppressed, thereby making it possible to suppress deteriorationof cooling performance. Also, since the inflow of the gas-phaserefrigerant into the expansion valve can be suppressed, the generationof noise from the expansion valve can be suppressed.

Also, according to a third aspect of the invention, there is provided acooling module wherein the supercooling portion 220 is arranged on theside of the condensing portion 210 far from another heat exchange unit300 in a vertical direction.

In the integrated heat exchanger 1, the supercooling portion 220, thecondensing portion 210 and another heat exchange unit 300 are increasedin temperature in that order. By arranging another heat exchange unit300 highest in temperature at a distance from the supercooling portion220 lowest in temperature, heat transfer from another heat exchange unit300 to supercooling portion 220 can be avoided. As a result, heatexchange performance of the condenser unit 200 can be more positivelyobtained.

In the cooling module according to the first to third aspects describedabove, the condenser unit 200 may be configured of a plurality ofstacked first tubes 2 a with the refrigerant passed therethrough andanother heat exchange unit 300 configured of a plurality of second tubes2 b stacked in the same direction as the first tubes 2 a with anotherfluid passed therethrough, while the integrated heat exchanger 1 mayhave a pair of header tanks 5 arranged at the longitudinal ends,respectively, of the first and second tubes 2 a, 2 b and communicatingwith a plurality of the first and second tubes 2 a, 2 b by extending inthe direction in which the first and second tubes 2 a, 2 b are stacked,so that the condenser unit 200 and other heat exchange unit 300 may beintegrated by header tanks 5.

The heat source unit may also be an intercooler (100) arrangeddownstream of a supercharger for pressurizing the intake air of theinternal combustion engine in the intake air flow to cool the intake airby heat exchange between the intake air and air.

Further, another heat exchange unit may be an oil cooler unit 300 forcooling the oil of on-vehicle devices.

Incidentally, reference numerals attached to the respective meansdescribed above represent correspondence with the specific means,respectively, described in the embodiments below.

The present invention may be more fully understood from the descriptionof preferred embodiments of the invention, as set forth below, togetherwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the cooling module mounted on the vehicleaccording to an embodiment of the invention.

FIG. 2 is a sectional view showing the integrated heat exchanger 1according to an embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the invention is explained below with reference toFIGS. 1 and 2. A cooling module according to this embodiment used in avehicle driven by an internal combustion engine as a drive source istaken as an example. FIG. 1 is a diagram showing the cooling moduleaccording to this embodiment mounted on the vehicle.

As shown in FIG. 1, the cooling module according to this embodiment,mounted at the front end of a vehicle, includes an integrated heatexchanger 1 having a condenser unit 200 and an oil cooler unit 300, andan intercooler 100. The intercooler 100 is an air-cooled heat exchangerarranged downstream of a supercharger (not shown) for pressurizing theintake air of the internal combustion engine to cool the intake air byheat exchange between the intake air and air. Incidentally, theintercooler 100 corresponds to the heat source unit according to theinvention.

The integrated heat exchanger 1 is arranged downstream of theintercooler 100 in the air flow (in the rear of the vehicle). The lengthof the integrated heat exchanger 1 in the vertical direction (verticaldirection on the vehicle) is larger than the vertical length of theintercooler 100. According to this embodiment, the vertical length ofthe intercooler 100 is larger than the vertical length of thesupercooling portion 220 of the condenser unit 200 described later andthe vertical length of the oil cooler unit 300. Also, the lower end ofthe integrated heat exchanger 1 and the lower end of the intercooler 100are located at the same vertical position.

FIG. 2 is a sectional view showing the integrated heat exchanger 1according to this embodiment. As shown in FIG. 2, the integrated heatexchanger 1 according to this embodiment includes one core unit 4 havinga plurality of tubes 2 and fins 3 and a pair of header tanks 5 assembledat the left and right ends, respectively, of the core unit 4.

Tubes 2, in which a heat medium (the refrigerant or the oil in thisembodiment) flows, each assume such a flat form that the direction ofair flow (perpendicular to the page) coincides with the direction alongthe long diameter thereof. A plurality of tubes 2 are arranged inparallel to each other in the vertical direction in such a manner thatthe longitudinal direction thereof coincide with the horizontaldirection. Fins 3 assume a corrugated form and are coupled to the flatsurfaces on both sides of each tube 2. Fins 3 increase the heattransmission area with air and promote heat exchange between the heatmedium and the air. Also, an insert 6 extending substantially inparallel to the length of tubes 2 to reinforce core unit 4 is arrangedat each end of core unit 4.

Header tanks 5 extend in the direction perpendicular to the length oftubes 2 at the longitudinal ends of the tubes (left and right ends inthis embodiment) and communicate with the plurality of the tubes 2. Theheader tanks 5 each include a core plate 5 a coupled to the tubes 2inserted therein and a tank body 5 b making up the inner space of thetank with the core plate 5 a. The header tank 5 located on the left sidein FIG. 2 is called a first header tank 51, and the header tank locatedon the right side in FIG. 2 a second header tank 52.

The core unit 4 is comprised of a condenser unit 200 for cooling therefrigerant by heat exchange between the refrigerant circulated in thevehicle refrigeration cycle (air conditioning system) and air, and anoil cooler unit 300 for cooling the oil in the torque converter for theautomatic transmission of the vehicle. According to this embodiment, thecondenser unit 200 is arranged on the upper side, and the oil coolerunit 300 on the lower side. The plurality of tubes 2 which make up thecondenser unit 200 in which the refrigerant flows are called first tubes2 a, and tubes 2 which make up oil cooler unit 300 in which the oilflows are called second tubes 2 b. Oil cooler unit 300 corresponds tothe other heat exchange unit according to the invention.

A tube arranged in the boundary between the condenser unit 200 and theoil cooler unit 300 (between first tubes 2 a and second tubes 2 b) makesup a dummy tube 6 through which no heat medium flows. According to thisembodiment, dummy tube 6 has the longitudinal ends thereof closed.

First separators 71 are arranged above and below, respectively, thedummy tube 6 in each header tank 5. As a result, the interior of eachheader tank 5 is divided into two parts along the length (verticaldirection) thereof by the first separators 71 as a boundary.

Now, the configuration of the oil cooler unit 300 will be explained. Theoil cooler unit 300 is a U-turn type with the oil flowing along theshape of a U. At the portion lower than the two first separators 71 inthe first header tank 51 (hereinafter referred to as the first oilheader portion 51 a), an oil inlet 31 allowing the oil to flow into theoil cooler unit 300 and an oil outlet 32 allowing the oil to flow out ofthe oil cooler unit 300 are arranged. The oil inlet 31 and the oiloutlet 32 are arranged at the lower and upper ends, respectively, of thefirst oil header unit 51 a.

In order to form the U-shaped oil flow in the oil cooler unit 300, asecond separator 72 is arranged in the first oil header portion 51 a.More specifically, the second separator 72 is arranged between the oilinlet 31 and the oil outlet 32 in the first oil header portion 51 a.

Now, the configuration of condenser unit 200 will be explained. Arefrigerant inlet 21 for allowing the refrigerant to flow into condenserunit 200 and a refrigerant outlet 22 for allowing the refrigerant toflow out of condenser unit 200 are arranged at the portion (hereinafterreferred to as the first refrigerant header portion 51 b) above the twofirst separators 71 of the first header tank 51. The refrigerant inlet21 and the refrigerant outlet 22 are arranged at the lower and upperends, respectively, of the first refrigerant header portion 51 b.

A third separator 73 is arranged at the position on the upper side inthe first refrigerant header portion 51 b, and a fourth separator 74 atthe same height as the third separator 73 is arranged in the portion(hereinafter referred as the second refrigerant header portion 52 b)above the two first separators 71 of the second header tank 52. Thecondenser unit 200 is divided into two heat exchange units by the thirdand fourth separators 73, 74.

A gas-liquid separator 8 is arranged on the outside (far from the coreunit 4) of the second refrigerant header portion 52 b. This gas-liquidseparator 8 is a receiver adapted to store the liquid-phase refrigerantby separating the gas-phase and liquid-phase refrigerants from eachother.

The gas-liquid separator 8 and the second refrigerant header portion 52b communicate with each other at two points through first and secondcommunication passages 81, 82. Specifically, the first communicationpassage 81 establishes communication between the lower end portion ofthe second refrigerant header portion 52 b and the lower portion of thegas-liquid separator 8. Also, the second communication passage 82establishes communication between the upper portion of the gas-liquidseparator 8 and the portion of the second refrigerant header portion 52b above the fourth separator 74.

First, the portion of the condenser unit 200 under the third and fourthseparators 73, 74 makes up a condensing portion 210 for condensing therefrigerant by heat exchange between the gas-phase refrigerant flowingin from the refrigerant inlet 21 and air. The refrigerant that hasflowed out of the condensing portion 210 flows into the gas-liquidseparator 8 through the first communication passage 81.

The portion of the condenser unit 200 above the third and fourthseparators 73, 74, on the other hand, makes up a supercooling portion220 for cooling the liquid-phase refrigerant by heat exchange betweenthe liquid-phase refrigerant flowing in through the second communicationpassage 82 from the gas-liquid separator 8 and air. The refrigerant thathas been cooled by the supercooling portion 220 flows out from therefrigerant outlet 22.

Now, the configuration of the gas-liquid separator 8 will be explained.The interior of the gas-liquid separator 8 is divided into an upperspace 83 and a lower space 84. The upper space 83 is connected to thesecond communication passage 82, and the lower space 84 to the firstcommunication passage 81. The liquid-phase refrigerant large in specificgravity flowing in from the first communication passage 81 staystemporarily in the vertically lower part (along the direction ofgravity) of the lower space 84 while the gas-phase refrigerant small inspecific gravity temporarily stays in the vertically upper part (alongthe direction of gravity) in the lower space 84.

The gas-liquid separator 8 includes a communication pipe 85 forintroducing the liquid-phase refrigerant in the neighborhood of thebottom portion of the lower space 84 into the upper space 83. A baffleplate 85 for improving the gas-liquid separability is arranged in thepart of the lower space 84 lower than the first communication passage81. Also, a dryer 86 containing therein a desiccant for removingmoisture in the refrigerant is arranged in the lower space 84. Further,a filter 87 for removing foreign matter from the refrigerant is arrangedin the upper space 83.

According to this embodiment, the first communication passage 81 isarranged below a normal liquid level (indicated by dashed line in FIG.2) of the liquid-phase refrigerant in the lower space 84. As a result,the intrusion of the gas-liquid two-phase refrigerant into thecommunication pipe 85 is prevented which otherwise might be caused byinvolving the gas-phase refrigerant existing above the liquid levelunder a dynamic pressure exerted on the liquid surface of theliquid-phase refrigerant flowing into the lower space 84 from the firstcommunication passage 81. Incidentally, intrusion of the gas-liquidtwo-phase refrigerant into communication pipe 85 causes the intrusion ofthe gas-phase refrigerant into the supercooling portion 220 and reducesthe supercooled area, resulting in a lower cooling performance.According to this embodiment, in contrast, the deterioration of thecooling performance is prevented by arranging the first communicationpassage 81 under the normal liquid level of the liquid-phase refrigerantin the lower space 84.

Returning to FIG. 1, the oil cooler unit 300 is arranged insuperposition with the intercooler 100 as viewed along the direction ofair flow. The supercooling portion 220, on the other hand, is arrangednot to be superposed with the intercooler 100 as viewed along thedirection of air flow (longitudinal direction of the vehicle). Also, thesupercooling portion 220 is arranged on the side of the condensingportion 210 vertically far from the oil cooler unit 300. According tothis embodiment, the supercooling portion 220 is arranged at the upperend and the oil cooler unit 300 at the lower end of the integrated heatexchanger 1, and the condensing portion 210 is interposed between thesupercooling portion 220 and the oil cooler unit 300.

By arranging the oil cooler unit 300 as described above in superpositionwith the intercooler 100 as viewed along the direction of air flow, i.e.downstream of the intercooler 100 in the air flow where the airtemperature is high, the condenser unit 200 can be arranged at the partwhere the air temperature is comparatively low. As a result, the heatexchange performance of the condenser unit 200 is secured. In theprocess, the temperature of the heat medium (oil) passed through the oilcooler unit 300 is higher than the temperature of the heat medium(refrigerant) passed through the condenser unit 200, and therefore, theheat exchange performance of the oil cooler unit 300 is not extremelyreduced.

Also, the supercooling portion 220 constituting the part of thecondenser unit 200 which is required to be reduced in temperature is notarranged downstream of the intercooler 100 in the air flow, i.e. thearea high in air temperature. In this way, the heat exchange performanceof the condenser unit 200 is secured. In the process, refrigerant whichmay boil in the supercooling portion 220 is suppressed, and thereforethe refrigerant flow rate in the expansion valve arranged downstream ofthe condenser unit 200 in the refrigerant flow is prevented frombecoming insufficient, thereby making it possible to suppress thedeterioration of the cooling performance. Also, since the intrusion ofthe gas-phase refrigerant into the expansion valve can be suppressed,the expansion valve is prevented from generating noise.

Also, in the integrated heat exchanger 1, the temperature of thesupercooling portion 220, the condensing portion 210 and the oil coolerunit 300 are higher in ascending order. For this reason, the oil coolerunit 300 is arranged on the side of the condensing portion 210 far fromthe supercooling portion 220. Specifically, the oil cooler unit 300highest in temperature and the supercooling portion 220 lowest intemperature are arranged at a distance from each other. Thus, the heattransfer from the oil cooler unit 300 to the supercooling portion 220can be avoided. As a result, the heat exchange performance of thecondenser unit 200 can be secured more positively.

Other Embodiments

According to the embodiments described above, the other heat exchangeunit makes up the oil cooler unit 300 for cooling the oil in the torqueconverter for the automatic transmission of the vehicle. Nevertheless,the invention is not limited to such an application, and a oil coolerunit for cooling engine oil or power steering fluid may be used.

Also, according to the embodiments described above, the supercoolingportion 220 is arranged at the upper end and the oil cooler unit 300 atthe lower end of the integrated heat exchanger 1. Alternatively, thesupercooling portion 220 may be arranged at the lower end and the oilcooler unit 300 at the upper end of the integrated heat exchanger 1.

Further, the lower end of the integrated heat exchanger 1 and the lowerend of the intercooler 100, though located at the same vertical positionaccording to the embodiments described above, may alternatively bedisplaced from each other.

Also, according to the embodiments described above, the oil cooler unit300 is arranged in superposition with the intercooler 100 in itsentirety as viewed from the direction of air flow. Nevertheless, theinvention is not limited to this configuration, and the oil cooler unit300 may alternatively be arranged in superposition at least partiallywith the intercooler 100.

While the invention has been described by reference to specificembodiments chosen for purposes of illustration, it should be apparentthat numerous modifications could be made thereto by those skilled inthe art without departing from the basic concept and scope of theinvention.

1. A cooling module comprising: a heat source unit; and an integratedheat exchanger including a condenser unit for cooling a refrigerantcirculated in a refrigeration cycle by heat exchange between therefrigerant and air, and another heat exchange unit for cooling anotherfluid higher in temperature than the refrigerant by heat exchangebetween another fluid and air; wherein the condenser unit and anotherheat exchange unit are vertically arranged in parallel to each other,wherein the integrated heat exchanger is arranged downstream of the heatsource unit in the air flow, wherein the vertical length of theintegrated heat exchanger is larger than the vertical length of the heatsource unit, and wherein another heat exchange unit is arranged insuperposition with at least a part of the heat source unit as viewedfrom the direction of air flow.
 2. The cooling module according to claim1, wherein the condenser unit includes a condensing portion forcondensing the refrigerant and a supercooling portion for supercoolingthe refrigerant flowing in from the condensing portion.
 3. A coolingmodule comprising: a heat source unit; and an integrated heat exchangerincluding a condenser unit for cooling a refrigerant circulated in arefrigeration cycle by heat exchange between the refrigerant and air andanother heat exchange unit for cooling another fluid higher intemperature than the refrigerant by heat exchange between another fluidand air; wherein the condenser unit and the heat exchange unit arevertically arranged in parallel to each other, wherein the integratedheat exchanger is arranged downstream of the heat source unit in the airflow, wherein the vertical length of the integrated heat exchanger islarger than the vertical length of the heat source unit, wherein thecondenser unit includes a condensing portion for condensing therefrigerant and a supercooling portion for supercooling the refrigerantflowing in from the condensing portion, and wherein the supercoolingportion is arranged not to be superposed with the heat source unit asviewed from the direction of the air flow.
 4. The cooling moduleaccording to claim 3, wherein the supercooling portion is arranged onthe side of the condensing portion far from another heat exchange unitin vertical direction.
 5. The cooling module according to claim 1,wherein the condenser unit is configured of a plurality of stacked firsttubes with the refrigerant passed therethrough, wherein another heatexchange unit is configured of a plurality of second tubes stacked inthe same direction as the first tubes with another fluid passedtherethrough, wherein the integrated heat exchanger has a pair of headertanks arranged at the longitudinal ends, respectively, of the first andsecond tubes and communicating with the plurality of the first andsecond tubes by extending in the direction in which the first and secondtubes are stacked, and wherein the condenser unit and another heatexchange unit are integrated with each other by the header tanks.
 6. Thecooling module according to claim 1, wherein the heat source unit is anintercooler arranged in the intake air flow downstream of a superchargerfor pressuring the intake air of the internal combustion engine andadapted to cool the intake air by heat exchange between the intake airand air.
 7. The cooling module according to claim 1, wherein anotherheat exchange unit is an oil cooler unit for cooling the oil of theon-vehicle devices.